Tilting drive for metallurgical vessels such as steel mill converters



KARLHEINZ MAHRINGER ETAL TIL-TING DRIVE FOR METALLURGICAL VESSELS Aug. 5, 1969 SUCH AS STEEL MILL CONVERTERS 2 Sheets-Sheet 2 Filed May 2 4, 1968 INVENTORS' manwmv: Mu

RIM BY h'ul-IIElNZ LAWLITZ 7,14%]; a, ATTORNES United States Patent 3,459,068 TILTING DRIVE FOR METALLURGICAL VESSELS SUCH AS STEEL MILL CONVERTERS Karlheinz Mthringer, Duisburg-Hamborn, and Karlheinz Langlitz, Mulheim (Ruhr), Germany, assignors to Demag Aktiengesellschaft, Duisburg, Germany Filed May 24, 1968, Ser.,No. 731,853 Claims priority, application Germany, May 27, 1967, D 53,185 Int. Cl. F1611 37/06 US. Cl. 74-665 Claims ABSTRACT OF THE DISCLOSURE A pair of steel mill converters are positioned in laterally adjacent spaced relation for tilting about respective pivot axes which are coaxial with each other and unconnected to each other. Each pivot has a respective main gear secured thereto outboard of a respective pivot bearing. Each main gear is enclosed within a respective gear housing which is restrained against rotation but displaceable to accommodate tilting of the respective pivot. Plural gear assemblies are provided for each converter, the gear assemblies being arranged in pairs which are opposite each other, with one gear assembly of each pair being respective to each converter main gear. Two relatively small power electric motors are provided for each pair of gear assemblies, and coupling means are provided whereby either one or both motors of each pair of motors may be connected to either one or both of the associated gear assemblies.

Background of the invention Multi-motor-powered tilting drives for smelting furnaces are known, for example, from German Patent No. 1,117,622. However, the purpose of the known solution is to provide a drive which takes into account the respectively dilferent torques required at any given time during the operation. In some periods of the blasting operation, it is possible to operate the drive with a motor having a lower power than that of motors used during other periods of the blasting operations.

However, the criterion of a tilting drive for metallurgical vessels is not only to supply the time-dependent torque but also to maintain a tilted position of the vessel for a long period. It happens repeatedly that slanting, bending, or canting of the pivot pins of the vessel prevents the required theoretical tooth engagement between the gear on the pivot pin and a stationary gear, so that tooth breakage leads to failure of the gears. Serious situations occur in a steel mill when the failure of a gear occurs when the metallurgical vessel or furnace is in an unfavorable and possibly unstable tilted position. At least in such cases, the damaged gear must be replaced if disaster is to be avoided, and such replacement generally requires several days time.

In some cases, complete sets of replacement gears are kept in stock or on hand, and damaged gears are replaced, it necessary, so that the down time or stoppage time can be reduced. However, a system of exchanging replacement gears for damaged gears still requires an expensive inventory, so that the required additional investment counteracts the effect of shortening the stoppage time.

Since most converters are arranged in series, the interruption of the operation of a single converter, in case of a failure of a gear, is particularly obstructive of the remaining operations at a converter platform or working station. As the repair operations take a considerable time, monopolize the conveyor or transport means of the plant, and frequently interrupt normal operations in an unac- 3,459,068 Patented Aug. 5, 1969 Summary of the invention This invention relates to tilting drives for metallurgical vessels, such as steel mill converters, and, more particularly, to an improved tilting drive operating through a gear secured on a pivot for tilting the vessel and to which one or more motors can be selectively coupled.

It is the purpose of the present invention to provide a tilting drive for metallurgical converters operating with a greater reliability and in which any possible failure results in minimum interference with the tilting operation of adjacent vessels or converters. As a feature of the invention, a converter which is in a tilted position, such as the blasting position, pouring position, or charging position, can be easily maintained in the tilted position and then returned to the erect position.

In accordance with the invention, gear units are arranged between two furnace vessels or the like in overhung or outboard position on the coaxial pivot pins of the furnace vessels, the gear units being locked or fixed on the pivot pins. By means of couplings, these gear units can be coupled selectively to one or plural motors of low individual power ratings. The gear units are arranged in housings which are stationary and torque-resistant.

An arrangement of this type has many advantages, the primary one of which is the great reliability of the tilting operation. Furthermore, in case of a failure related to one furnace vessel, it is possible to changeover immediately. Thereby, the power of a motor at that time driving a defective gear can be used to continue the operation through an elfective gear unit. Additionally, the gear units, being arranged in overhung or outboard relation, provide a more effective protection against tooth breakage than has been the case up to the present, so that troubles and difficulties will occur with less frequency. Nevertheless, the overall size of the drive is not increased over that of a known drive, because the lower ratings of the several motors included in the drive result in lower motor weights. The replacement or exchange of a smaller motor can be provided without any greater difliculty than hitherto encountered.

The invention thus combines the advantages of a pivot pin gear arranged in overhung or outboard arrangement with the selectivity of power application to either of two adjacent metallurgical vessels or converters. This results in substantial savings in the necessary investment. In addition, low-powered drives can be kept in stock, procured, or ordered in numbers or quantities that are easier to calculate.

In accordance with a further feature of the invention, the individual driving motors have hinged supports on the respective gear units or assemblies. Thereby, it is possible to equalize any sagging or canting of the pivot pins of furnace vessels arranged in pairs, and using only the motor support or supports. In addition to elastic couplings, there are other hinge-like constructions which are known from the technique of axle equalization.

'In accordance with a further feature of the invention, all of the individual driving motors are arranged on the gear unit below the converter platform. The trend in steel mills is to provide, on converter platforms, the corresponding prerequisites for the constantly increasing requirements which a product must meet. It is particularly important to attain complete utilization of the available space, so that efforts are being made to utilize the free space on the converter platform for working, and to use the corresponding space in the upper region for all types of aggregates, charging means, drives, etc. The provision of driving motors arranged below the converter platform is particularly favorable for this purpose, and also enhances the ease of attention to the motors since the motors are more easily accessible than heretofore. The gear units may comprise planetary gears, as such gears are completely enclosed and form a unit which is very insensitive to dirt and which has proved successful in rugged metallurgical operations. Additionally, such a unit is easier to attach, as a unit, to the pivot pin or to detach as a unit therefrom. The advantages from the operational and assembly standpoint are therefore combined in a planetary gear unit.

As a further feature of the invention, a single control can be provided for all of the motors of the two gear units. The operation of the pair of furnaces or converters can thus be made certain and can be automated to a great extent. For example, by manipulating the automatic controls, it is possible to operate, alternately, one or the other furnace vessel, engaging only the respective coupling or couplings. Also, for example, the switching to another power drive train, in the case of a failure in one train, can be effected at the time of failure of a drive part.

A particularly important feature of the invention is the arrangement of a reduction gearing assembly ahead of each gear unit, and which reduction gearing assembly is driven by a single driving motor. The gear arrangement is thus divided into individual smaller groups which can be kept in stock more economically and which are also of a substantial help in that they can be assembled in the drive or disassembled therefrom in a much shorter time.

A particularly advantageous embodiment of the present invention involves arranging the reduction gear assemblies in pairs, with each pair having associated therewith two driving motors and with the couplings of each motor to the two gear assemblies of each pair being arranged in opposition. This arrangement has the advantage that it is possible to work the tilting drive with even smaller drive units than heretofore. A further advantage, apart from the considerations of economy, is the technical effect of lower costs for switching arrangements as well as a further simplification of the handling in the case of trouble. In the unlikely case of a failure of a gear, which can be caused by unforeseen coincidences despite all the care used in manufacture and in testing of the material, one side of the furnace can be so layed out, for example, that four gear assemblies are provided and that an output of 75% of the available output is always assured using three gears assembly. This would be sufficient to maintain operation for a short period of time. With this improvement, however, using increasingly smaller driving motors, the number of individual motors is increased so that, if a single drive fails, a smaller amount of power is lost. Thus, the smaller each driving unit is, the greater is the reliability of the tilting operation for continued working during periods of failure without resulting in stoppages and without inhibiting the operaton of adjacent metallurgical vessels or converters.

An object of the invention is to provide an improved tilting drive for metallurgical furnaces such as steel mill converters.

Another object of the invention is to provide such a drive which is more reliable than known tilting drives and which, upon failure, interferes less with the operation of adjacent metallurgical vessels or converters.

A further object of the invention is to provide such a drive in which a metallurgical vessel or steel mill converter, when tilted to a selected position for a particular operation, can be readily maintained in the tilted position and can then be brought back to the erected position.

Yet another object of the invention is to provide such a tilting drive in which two furnace vessels are arranged in adjacent relation with gear units positioned therebetween in overhung or outboard position and in driving engagement with pivot pins for tilting the vessels.

A further object of the invention is to provide such a tilting drive as just-mentioned in which the gear units can be selectively coupled to one or more of a plurality of relatively small capacity motors.

Still another object of the invention is to provide such a tilting drive in which the gear units are arranged in stationary housings which are torque-resistant.

A further object of the invention is to provide such a tilting drive in which all of the individual driving motors connected to a gear unit are positioned below a supporting platform for the converters.

Yet another object of the invention is to provide such a tilting drive in which the gear units consists of planetary gears.

A further object of the invention is to provide such a tilting drive in which a single control is provided for all motors of two gear units.

Another object of the invention is to provide such a tilting drive in which a reduction gear assembly is positioned in advance of each gear unit and driven by a single driving motor.

Brief description of the drawings For an understanding of the principles of the invention, reference is made to the following description of typical embodiments thereof as illustrated in the accompanying drawings.

In the drawings:

FIG. 1 is a side elevation view, partly in section, of a pair of converters with an interposed driving unit and connecting means in accordance with the invention;

FIG. 2 is a partial top plan view and partial horizontal sectional view corresponding to FIG. 1 and taken on the line 22 of FIG. 1;

FIGS. 3 and 4 are vertical sectional views taken on the correspondingly numbered lines of FIG. 2; and

FIG. 5 is a somewhat schematic vertical sectional view, corresponding generally to FIG. 3, but with certain gears omitted and a main gear shown in dot and dash outline only.

Description of the preferred embodiments Referring first to FIGS. 1 through 4, converters 1 and 2 are vertically oriented and arranged in laterally spaced relation on a converter supporting platform 3, so that the converters can be tilted by a common gear assembly generally indicated at 4. Each converter is supported, by means of the usual claws (not shown), in a respective supporting ring 7 or 8, and supporting rings 7 and 8 have respective converter-tilting pivots 5 and 6. Pivots or pivot pins 5 and 6 are supported in bearings on respective tilting frames 9 and 10, and each pivot pin carries, supported in overhung or outboard relation, a respective gear unit 11 and 12. Gear unit 11 has operatively associated therewith two reduction gear assemblies 13 and two reduction gear assemblies 14, and gear unit 12 has operatively associated therewith two reduction gear assemblies 15 and two reduction gear assemblies 16. Gear assembly 4 thus comprises eight reduction gear assemblies, four associated with each of the two gear units. A plurality of low power electric drive motors 17 are associated with the reduction gear assemblies, the number of drive motors 17 being equal to the number of reduction gear assemblies. By reference to FIG. 2, it will be noted that the drive motors 17 are arranged in pairs, each pair of drive motors 17 being arranged for selective coupling to either of a pair of reduction gear assemblies, one operatively associated with gear unit 11 and the other operatively associated with gear unit 12, as will be described more fully hereinafter.

As best seen in FIGS. 1, 3 and 4, articulated or swivel connections 18 extend between reduction gear assemblies 13, 14 and 15, 16 and a retaining means 19 on the housing 20 of the associated gear unit 11 or 12, respectively. Each housing 20 has a projection 22 extending into a iixed abutment means 21 on the frame 9 or 10, the elements 21 and 22 constituting torque-resistant means preventing turning of the respective housing 20 during transmission of power from motors 17 through the reduction gear assemblies to the main gears secured to the respective pivots 5 and 6. However, the interconnections 21, 22 provide for relative displacemnt of housings 20 and frames 9 and 10 responsive to sagging or canting of the respective pivot pins 5 or 6. This displacement is also facilitated by the disengageable flexible couplings 23 connecting each motor 17 to a gear of a reduction gear assembly.

As best seen in FIGS. 3 and 4, the reduction gear units 13, 14 and 15, 16 form a substantially radial arrangement on the circumference or periphery of the associated gear units 11, 12, respectively. Two individual driving motors 17, of relatively low power or rating, are operatively associated with each axially opposite pair of reduction gear assemblies, and can be selectively coupled, through couplings 23, to drive either of the gear units 11 or 12.

In the embodiment of the invention shown in FIGS. 1 through 4, reduction gear assemblies 14 and 15 are arranged above the converter platform 3, and reduction gear assemblies 13 and 16 are arranged below converter platform 3. However, in the arrangement shown in FIG. 5, all of the reduction gear units 13, 14 and 15, 16 are arranged below converter platform 3. Thereby, considerable savings in space can be attained in the upper region of the converter blasting stand, as mentioned above. Otherwise, the arrangement of gear units 11 and 12 corresponds to that described for FIGS. 1 through 4.

Gear units 11 and 12 may comprise, within their respective closed housings 20, a planetary gear drive, with the advantages previously mentioned. Control of driving motor 17 is effected substantially completely by electrical means, and it is not believed necessary to describe the electrical connections of the motors or their control.

For scheduled or purposeful interruptions of the operation of the tilting drive, such as for relining a converter, converter pivot pins 5 and 6 can be locked by means of brakes, stops, etc., so that the driving units and the motors are loaded during these interruptions.

While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.

What is claimed is:

1. Tilting drive arrangement for metallurgical vessels, such as steel mill converters, comprising, in combination, a pair of metallurgical vessels each having pivot pins for tilting of the vessel; means supporting said vessels in laterally spaced adjacent relation with their pivot pins in substantially coaxial opposition with each other, and including bearing means supporting the opposed pivot pins intermediate the ends of the latter; a pair of main gear units disposed between said vessels and supported on respective opposed pivot pins outboard of the associated bearing means, each main gear unit including a main gear, secured to rotate with the associated pivot pin, and a respective housing enclosing the unit; plural relatively low power motors disposed between said converters; and respective coupling means selectively operable to couple said motors to either main gear unit to drive the latter; whereby either main gear unit may be driven by from one to all of said motors.

2. Tilting drive arrangement for metallurgical vessels, as claimed in claim 1, including interengaging means on each housing and on said supporting means restraining rotation of the associated housing, responsive to torque applied to the associated main gear unit, while providing for non-rotational displacement of the associated housing to accommodate deflection of the associated pivot pin.

3. Tilting drive arrangement for metallurgical vessels, as claimed in claim 2, in which said respective coupling means flexibly couple the associated motors to said main gear units.

4. Tilting drive arrangement for metallurgical vessels, as claimed in claim 2, in which said supporting means comprises a converter platform; all of said motors being mounted below said converter platform.

5. Tilting drive arrangement for metallurgical vessels, as claimed in claim 2, in which each main gear unit comprises a planetary gear assembly.

6. Tilting drive arrangement for metallurgical vessels, as claimed in claim 2, including a reduction gear assembly interposed between each motor and each of said main gear units, each reduction gear assembly being driven by at least one of said motors.

7. Tilting drive arrangement for metallurgical vessels, as claimed in claim 1, including common control means for all of said motors.

8. Tilting drive arrangement for metallurgical vessels, as claimed in claim 1, including plural reduction gear assemblies operatively coupled to said main gear units, the number of reduction gear assemblies coupled to one main gear unit being equal to the number of reduction gear assemblies connected to the other main gear unit; said reduction gear assemblies being arranged in axially opposed pairs each including one reduction gear assembly coupled to one main gear unit and a second reduction gear assembly coupled to the other main gear unit; said motors being arranged in pairs with each pair of motors being operatively associated with a respective pair of axially opposed reduction gear assemblies for selective coupling to either or both thereof by said coupling means.

9. Tilting drive arrangement for metallurgical vessels, as claimed in claim 8, in which one motor of each pair is selectively connectable by said coupling means to a first gear of the associated pair of reduction gear assemblies and the other motor of each pair is selectively connectable by said coupling means to a second gear of the associated pair of reduction gear assemblies.

10. Tilting drive arrangement for metallurgical vessels, as claimed in claim 8, in which each reduction gear assembly include an output gear in engagement with a respective main gear unit for supporting of the associated reduction gear assembly in an articulated manner with respect to the associated main gear unit; and interengaging means on each reduction gear unit and the associated main gear unit housing restraining angular displacement of the associated reduction gear assembly about the axis of its output gear.

References Cited UNITED STATES PATENTS 3,201,106 8/1965 Lafax. 3,207,002 9/ 1965 Lakin et a1. 3,333,801 8/1967 Falk. 3,373,626 3/1968 Maurer et a1.

DONLEY J. STOCKING, Primary Examiner L. H. GERIN, Assistant Examiner US. Cl. X.R. 74-4l0; 266-36 

